package zjh_20230309;

import java.util.Hashtable;
import java.util.Map;

public class Demo01{
     static Map map = Map.of("1","a","2","b");
     static Map map1 = Map.copyOf(map);

    public static void main(String[] args) {
        System.out.println( map.get("1"));
        System.out.println(map1);
        Hashtable h = new Hashtable();
        h.put(1,"2");
        h.put(5,"1");
        System.out.println(h.toString());
    }
}
